Abstract: Recently, cannabinoids have been shown to
possess antitumor properties. Because the psycho-activity of cannabinoid
compounds limits their medicinal usage, we undertook the present study to
evaluate the in vitro antiproliferative ability of CBD, a non- psychoactive
cannabinoid compound, on U87 and U373 human glioma cell lines. The addition of
CBD to the culture medium led to a dramatic drop of mitochondrial oxidative
metabolism (MTT test) and viability in glioma cells, in a
concentration-dependent manner, already evident 24 h after CBD exposure with an
apparent IC50 of 25 µM. The antiproliferative effect of CBD was partially
prevented by the CB2 receptor antagonist SR144528 and -tocopherol. By contrast,
the CB1 cannabinoid receptor antagonist SR141716, capsazepine (vanilloid
receptor antagonist), the inhibitors of ceramide generation or PTX did not
counteract CBD effects. We also show, for the first time, that the
antiproliferative effect of CBD was correlated to induction of apoptosis, as
determined by cytofluorimetric analysis and ssDNA staining, which was not
reverted by cannabinoid antagonists. Finally, CBD administered s.c. to nude mice
at the dose of 0.5 mg/mouse, significantly inhibited the growth of
subcutaneously implanted U87 human glioma cells. Concluding, the
non-psychoactive CBD was able to produce a significant antitumor activity both
in vitro and in vivo, thus suggesting a possible application of CBD as an
antineoplastic agent.

*Industrial-Hemp has no
psychoactive properties following definition of the European Economic Community (EEC);
THC content is less than 0.3%. In general, low THC-seed varieties without psychoactive
properties are those that have a THC content of less than 1%. (See also No-THC Hemp-seed.)
THC= Delta-9 TetraHydroCannabinol.